This proposal requests funds to purchase a high-quality, high- resolution flourescence photomicroscope to be used by a group of staff members in the divisions of basic research at the Institute for Cancer Research and Population Oncology of the Fox Chase Cancer Center. The microscope will be used in research projects in cell and molecular biology, developmental biology, tumor induction and progression, and virology. Specific projects range from scanning of tissue sections and cell cultures for specific viral antigens and gene products to high-resolution, subcellular localization of proteins in individual cells. The investigators are productive and have good track records. Support is recommended.